FAQ

Q. How is a loop repaired after activation?A. Plastic optical fibre does not require special tools and can be re-joined in under a minute using our fast and economical field repair kits. The reality is electricians side cutters and some tape can effect a repair, this is certainly not recommended however illustrates the robust nature of the system. For short loops such as inside a circuit breaker it may be faster to simply replace with a new length. PyrOnodes can be either replaced or reset depending on access restrictions.

Q. How is the point of failure identified?A. An activated pyrOnode can be identified by visual inspection due to the detached POF segment and raised cutting element. Disturbing the POF core around a pyrOnode is another way to find activations. Generally a loop and relay would be provided for each sub circuit or equipment section in the same way as electrical protection is provided. Should an activation ever occur knowing exactly where in the loop prior to access is of limited practical value. This is because isolation of the entire section will be required to gain access for repair work, at which time the exact point of failure is quickly and easily identified.

Q. How is this an efficient solution if the loop needs repair after activation?A. Connection failure is typically a low frequency event, anything other than this and there is an underlying design issue or the installation has reached a point where overhaul or replacement is required. The effort to splice or replace the fibre is inconsequential to the repair activity that will be needed should an activation occur. The reality is other online systems force you to make a connection at every point during installation even though most will never fail, now that's inefficient! Sensor connections themselves are a potential point of failure, PyrOptic virtually eliminates this problem by trading off the limited practical value of individual connection discrimination.

Q. What makes PyrOptic so reliable?A. PyrOptic is a new take on old technology, thermostat wax. This material can be found in everything from planes and automobiles to greenhouses and heating systems. Thermostat wax rapidly expands during phase change, the temperature this occurs at is controlled during a multi phase manufacturing process resulting in an inert material with virtually indefinite life span. PyrOnodes are small thermal hydraulic actuators which capture this expansion to cut the optical fibre. Design features and functionality have been carefully considered to optimise the solution including the use of an unbroken optic loop and commercially available relays that can be sourced from multiple vendors . This simplicity is how PyrOptic can guarantee long term reliability.

Q. Thermal imaging uses temperature differential between phase connections to detect problems, is PyrOptic as effective?A. PyrOptic is more effective because it's monitoring 24/7, thermal imaging is intermittent. Differential temperature monitoring simply improves the chances of thermal imaging catching a problem provided a circuit is adequately loaded at the time of inspection.

Q. Alternative online monitoring systems can use temperature differential between phase connections to detect problems, is PyrOptic as effective?A. Differential monitoring will provide earlier alarm of developing issues. The value of this needs to be weighed up against the specific application requirements and if this advantage outweighs the vastly increased complexity and life-cycle costs.

The practical reality is, in the majority of applications, threshold monitoring is more than adequate and will probably cover over 20 times the connections for the same upfront cost. Electrical connections have been around for a long time and are often part of type tested assemblies, failure is the exception, rather than the rule. So long as the end user knows about a deteriorating connection prior to insulation damage, most, if not all the benefit is achieved. This is what makes PyrOptic the truly optimised solution for the vast majority of electrical assets.

Q. Why monitor temperature?A. Electrical protection has never effectively manged connection degradation and thermal runaway. The world has recognised the hazards of joint failure in electrical systems for along time, for industry this is manifested in routine maintenance and inspections such as thermal imaging, for residential installations the electrical codes of Canada and the United Sates have mandated arc-fault circuit interrupter (AFCI) devices due to faulty domestic installations causing 40,000 residential fires each year resulting in 350 deaths and 1,400 injuries. Unfortunately the technology behind AFCIs won't detect glowing connections, also known as high resistance joints which can exceed temperatures of 1000°C. This has been a major criticism and for good reason, arcing faults are simply far less common than high resistance joints.

In business you need to manage risk and electrical assets are inherently so. AS/NZS 3000, section 1.5 Fundamental Principles specifies excessive temperatures as one of the three major electrical installation risks, reflecting a common theme throughout standards across the globe. Thermal runaway has historically been managed using a combination of design, installation verification and routine maintenance and inspection tasks. PyrOptic is a solution that monitors temperature, the most direct way to detect failing electrical joints. Deploying PyrOptic throughout an electrical installation can enable the elimination of thermal imaging, visual inspection and micro ohm testing routines. This results in improved safety and plant reliability at a lower cost.

It is not well understood that electrical connections have a design life and connection quality deteriorates with time due chemical reaction at the jointed surfaces. Operating temperatures, currents, surface materials and jointing methods are some of the factors in how fast the connection degradation occurs. As connections deteriorate their temperature increases, accelerating the chemical reaction and ultimately leading to thermal run away and catastrophic failure.

Q. How are PyrOnodes rated?A. PyrOnodes are available with activation temperatures ranging up to 105°C. Each PyrOnode temperature designation has detailed characterisation data, e.g. a PYR-82 has a maximum normal operating temperature limit of 76°C, above this the cutting mechanism begins to act on the optical fibre with a complete cut occurring at 82°C, furthermore the time to operate at 82°C is approximately 120 seconds and as the temperature increases above this the speed of operation becomes faster. Further information is available in the PyrOnode product section.

Q. What is the correct temperature limit to select?A. It’s best to understand the maximum normal operating temperatures of the equipment and then use a PyrOnode with a maximum operating temperature above this. If not already known, non-reversible thermal indication stickers/labels can be an effective, low cost and safe way to determine this (Tempil, Brady and Omega, to name a few)

Q. I don't know what the maximum normal operating temperature of the equipment is and it’s difficult to obtain, I do know the system uses insulation with X°C rating, does that help?A. Yes, choose a PyrOnode with a maximum operating temperature limit that's above the insulating rating. This method simply may not provide the earliest possible warning.

Q. What about selection for un-insulated bus bars?A. Ideally the highest normal operating temperature should be obtained. Otherwise as a general guide the temperature where accelerated connection surface deterioration occurs can be used. For example it's generally accepted that bare copper to copper connections should not operate above 88°C as oxides readily form above this temperature. A PYR-92 would allow excursions to 86°C and catch thermal runaway well before any damage occurred.

Q. Can I select a temperature rating thats too high?A. Generally speaking, for preventing catastrophic failures due to thermal run away, not really. When connection deterioration starts to occur it tends to go from hot to hotter. Even if a PYR-105 was installed on a V75 rated connection it would still provide useful alarming, its just that the chance of permanent damage to the insulation is increased.

Q. What signal comes out of the monitoring relay and how can it be used?A. Simple fibre optic amplifier relays typically have NPN and PNP open collector outputs. These can be used to drive digital inputs and interposing relays for plant alarms and automatic tripping of circuits. Relays with communication interfaces such as DeviceNet, EthernetIP and rs485 are also readily available.

Q. Can PyrOptic be used for other applications?A. Absolutley! PyrOptic is suited to risky yet infrequent events with application ranges up to 105°C. Additional functionality can be achieved such as accurately determining the position of a break using more advanced loop integrity check techniques such as Optical Time Domain Reflectometry (OTDR). Materials can also be changed to suit different environments e.g. stainless steel.